Electronic Brake Controller

I have a 2007 Tahoe and I bought a electronic brake controller. I found the 4 wires to make the connections to the unit. But the owners manual for the Tahoe says there are 2 curcuits that are wired but not connected under the hood. I found two red w/black stripe wires with eye ring connectors in different locations. But they are not labeled.

Where do theys 2 red wires connect to. Are they for the trailer braking system?